If anyone was listening on 10.1215 this morning it would have been obvious why IMO using split frequencies is a disaster on SOTA. ON6ZQ/P was clearly sending “UP” after each contact however I heard several phantom QSOs where the chaser was assuming the exchange was for them despite the fact they were sending on the wrong QRG. To really add confusion to the situation OK1MLP/P popped up on 10.122, what a mess!
73
Victor GI4ONL
I went split on only very few occasions while activating SOTA summits and I have made mixed experiences.
I was surprised that a bunch of chasers was immediately on my new RX frequency after I sent “up1”. I do remember that after about 10 - 15 stations the pile-up thinned out and I went back to my original listening frequency. There still was a pack calling on the frequency where I had not been listening for a while. It seems to me that the majority of SOTA chasers is not familiar with the concept of split operation and ignored my “up1”.
Nevertheless, going split can help you pull out a group of sharp operators, have fun working them and thin out the main pack. I will not work to get a clear calling frequency. A big part of the pile-up will remain on top of your calling frequency. In any case you will need a few kHz of empty band space above your QRG to make split operation work, a situation which is hard to find.
EDIT: This all refers to CW, in SSB the situation might be different.
Just my experience…
73 Heinz
Like Heinz I’ve worked SOTA split on occasions. It’s been beneficial at times but now I tough it out as, to be honest, I don’t raise pile-ups big enough to really justify split operations. That’s my opinion, if others feel split helps them then that’s fine.
I worked split when I put the first CT3 summit on the air and I think it helped me a lot. But that was on 18MHz and the band was quiet at the time. I worked the 1st few and thought, time for split and started sending UP. Brian G4ZRP was listening and he said there was much confusion. Within seconds of sending UP I had a manageable pile-up but Brian told me that lots continued to call on my original frequency. Then there people sending “LID QSX 1UP” etc. The end result, I was qualified and many people worked a new association, new summit and Africa for SOTA.
As the saying goes, YMMV.
IMHO, there can be NO excuse for a SOTA Activator working split…NEVER, EVER, EVER.
I’ve managed some huge SOTA pile-ups and never once considered working split.
73 Mike
2E0YYY
Nice summary:
Well, I’ve just worked Christophe on 30 metres and I must say it was very easy once you spotted where he was listening.
A panadaptor and dual receive helps naturally, but I’m sure most chasers use these as a matter of course?
There were a few stragglers calling on his frequency, but the majority were UP in the range +600 to +1200.
So yes, it makes life easy but only if everyone conforms to the UP!
I missed the earlier activation so no idea how that one panned out 
Pete
Hi Pete, I worked Christophe on 2 summits today when he was QSX up but I heard several WELL KNOWN chasers initially trying to call on his TX frequency. Obviously they only looked at his spot from RBN and didn’t actually listen to him very clearly sending “UP”. It did eventually appear to work better than the previous summit but FWIW I am still of the opinion we don’t need split QRG on SOTA.
73
Victor GI4ONL
My two-penny worth: IMHO split is actually counter-productive for SOTA. The reason that I say this is that most Activators are running QRP. It is the much higher powered chasers that are holding the frequency for the activator. If the pile-up is on a different frequency then there is a chance that another station will try and take over the activators frequency.
Brian
What is the most stressful part of SOTA CW Chasing ?
In the majority of cases this is due to the activator being the weakest station at the bottom of a pile-up. The chaser is attempting to tune in and read a QRP signal which is constantly being swamped by dozens of chasers running high power. Many chasers are also attempting to be the last tail-ender, with the result that readability of the activator is intermittent at best, with many “?” calls from chasers unable to read the callsign that the activator has just sent, which causes many repeats.
Now compare this with a split operation. All of a sudden the chaser is now reading the activator on a clear frequency and can tune in the weak signal from the activator to get the best readability possible. The pile up has been shifted and chasers can read everything sent by the activator.
Chris ON6ZQ was doing a good job working a huge pile up on 10 MHZ this morning. It was just unfortunate that on one of his activations another SOTA activator came up 1 KHz higher which caused chaos. This is always a possibility with split-working.
Successful split operation depends firstly on the activator sending his call and “up” after EVERY contact. Miss this just once and freshly joined chasers will naturally call on the activators frequency. However, there will always be enough policemen to shout “Up Up”.
The activator must also send his Ref. at frequent intervals.
With an experienced activator and responsive chasers the system will work well and provide a welcome relief for other chasers. However, 40m is too congested for SOTA split working.
73
Roy G4SSH
FWTW,
I have never felt the need to work split while on an activation; the pack soon gets thinned out either by me working through them quickly (contest style) or due to propagation change or by me running QRP for a while.
I don’t think there are enough chasers to warrant blocking two frequencies just yet.
Carolyn
Hi Roy, in theory that is exactly how it should work and does so for lots of DX stations. However as far as SOTA is concerned any time I have heard stations using split QRG, chaos has ensued!
You got it in one there but, unfortunately, in SOTA we don’t appear to have the required level of experience (in my humble opinion).
I couldn’t agree more, he was operating very professionally.
73
Victor GI4ONL
I worked Chris later when he was activating ON/ON-001 and using split. It seemed to me to be very orderly with little if any calling on Chris’s frequency. Split operation is quite infrequent on SOTA so perhaps it is just a case of Chasers not being use to it.
I think split operation on SSB and CW are quite different. I don’t really like split SSB because it tends to occupy a large amount of RF spectrum and it is often not easy to discover the DX station’s RX pattern. Split CW operation on the other hand tends to occupy much less space, usually within 2KHz up of the DX station. I have never found it too difficult chasing a DX station using split CW operation.
From my limited experience of activating I have found SSB pileups easier to handle than CW ones. For me it is a lot easier to pull out a couple of callsign letters out of a SSB pileup than the same situation in a CW pileup. Having said that a lot of CW Chasers deliberately call off frequency in the hope that makes their CW note more distinctive to the Activator. I think CW split could be a lot less stressful for the Activator.
So my opinion is: SSB Split - No Thanks!, CW Split - Good idea in a large pile up.
73 Andrew G4AFI
Split is the best solution when the pile-up is too big IMHO. If people should only listen !!!
ON6ZQ is a very good CW op and knows what he is doing…
As always in a pile up…listen listen listen. Also activators need to listen whether a frequency is free and they should not start on a frequency when there is a pile up on the qrg.
73
ON6UU
Hello Frank…
As always in a pile up…listen listen listen.<<
And that is the problem…some don´t listen. On a DX-Pedition everyone expect split operation, but not on a SOTA Activation. Christophe is a good operator and write in his alert, that he will use split, but on the first 2 Activations was chaos on his calling QRG. After almost every QSO he give UP(perfect!!) but some chaser don´t go to split. Also good cw-operator and well known chaser. That was the reason for my spot in SOTAWatch. At the last summit it was better, because most chaser now know about the split!
best regards de Tom
DL1DVE
P.S.: Everyone make mistakes, me included!
It seems folks can learn! 
Split working’s a mixed blessing, especially where there’s not much space, as is the case particularly on the WARC bands, and more so with SSB…
SOTA rules are stupid…
Vy 73 de Mariusz SP9AMH/QRP
P.S.
Sorry for my English…
Mariusz,
I don’t think power makes a lot of difference when working split.
I was able to work Christophe on 3 summits yesterday without any difficulty.
I also only chase with 5 Watts to an EF antenna.
With QRP, as you know, patience is the name of the game.
I’m very often the last caller in peoples log; I just wait for all the mayhem to disappear 
Not quite sure of the meaning of all but here’s my take on it.
Regards
73
Pete